Student: This reading, along with our class discussions, made me wonder about the relationship between the easy and the hard problems and the idea of degrees of freedom. How can we say that the easy problem uses all the degrees of freedom which prevents us from understanding the hard problem when we don’t know the complete truth of the easy problem? Isn’t there a possibility that feelings have a strictly physiological explanation the same way that the easy problem supposedly does? My question is more why do we assume that they are two different problems when we haven’t completely explained either?
SH: Good question. It opens a methodological and metaphysical Pandora’s Box — but one that, fortunately, only philosophers need to struggle with
The “Easy Problem” (EP) of Cognitive Science is the problem of explaining, causally, the cognitive capacities of thinking organisms, especially humans: How and why are they able to do all the cognitive (as opposed to “vegetative”) things they can do?
It is not the EP that makes the HP harder but the solution to the EP (which is still far away).
Will the EP ever be solved? Who knows. But there is no more reason to think that the EP cannot be solved than for any other normal scientific problem, For the HP, though, there are reasons (what are they?). But those are already what makes the EP hard.
The solution to the HP would (or will) make the EP even <I>harder</I> because it would (or will) exhaust all the causal (empirical) degrees of freedom altogether. Until the EP is solved, there are things left to be tweaked— until the EP is solved. “Tweaking” means there are still causal alternatives to try, and to test.
Until the EP is solved. But then, what’s left to try and to test? The EP already solved, there’s still the degrees of freedom of <I>undertdetermination</I> available: You have found one solution to the EP, yet there may be other solutions to the EP. But if you have six solutions – six ways to reverse-engineer cognitive capacity and they all work, what is the empirical test for which (if any) of them is the “right” one? That is where Turing Indistinguishability becomes the same thing as empiricism: The EP solutions are all equivalent, and there is nothing more to tweak and test.
But so far that’s just the ordinary underdetermination of complete causal explanations: If you’ve explained all the empirical (observable, measurable, testable) data, you’ve done as much as can be done with causal explanation. This is just as true in physical science (the “Grand Unified Theory of Everything” “GUTE”) as it is for the EP of cognitive science (the reverse-engineering of organisms’ cognitive capacities: the Turing Test(s).
The difference between cognitive science and physics, though, is the HP (sentience): How and why do sentient organisms <b>feel</b>, rather than just <b>do</b>? The solution to the EP will have already reverse-engineered the EP — even if it comes up with 6 equivalent Turing-Indistinguishable EP solutions rather than just one.
Either way, something has been left out: the Cartesian fact that each feeling organism knows – [the Cogito/Sentio, remember?] — which is that they feel. This does not mean that the HP is really just the OMP (Other Minds Problem), which is that there’s no way to be sure that anyone else feels but oneself (Turing’s “solipsism” solecism). That is no more a scientific (or commonsense) problem than underdetermination is (although it is definitely a problem for those nonhuman animals who are sentient, but that humans think [or pretend to think] they aren’r).
Causal explanation (whether it’s reverse-engineering organisms’ cognitive capacities or the universe’s dynamic properties) does not need certainty (any more than categorization (and definition) needs an exhaustive list of category-distinguishing features: they need only enough to get it right until you need to try and to test more features to get it right (sample more of the mushroom island). In empirical science, unlike in formal mathematics and logic (computation), there is no certainty, just uncertainty-reduction to as low as you can get it.
Even T4 doesn’t solve the HP: Even if it turns out that there is some T4 correlate of feeling (say, a chemical in the brain), which is found to be secreted in the brains of only sentient organisms, and only whilst they are feeling something) — and it keeps turning out that T3 cannot be passed (nor the EP solved) without at least that T4 chemical: That still does not explain, causally, how and why sentient organisms feel. T4 is, after all, just part of the EP. Correlates can be tweaked and tested, but the arbiter is still only EP. Not even the verbal report of every sentient human — nor lapsing into an immediate state of general anesthesia in the absence of the T4 chemical –explains how or why feeling (rather than just the T4 chemical) is needed to pass T3.
T4 correlates in EP don’t become causal explanations in HP.